This document describes the implementation status of checkpoints
defined in "User Agent Accessibility Guidelines 1.0". It is
meant to demonstrate that the requirements specified in the guidelines
can be implemented in existing and future user agents.

There is no implied or presumed endorsement of one type of
implementation or another type of implementation by reference in this
document. Inclusion serves only as an example to developers of the
viability of satisfying the requirements of a checkpoint.

This section describes the status of this document at the time
of its publication. Other documents may supersede this document. The
latest status of this document series is maintained at the W3C.

This document is support material for
User Agent Accessibility Guidelines 1.0 and is not meant to become a W3C
Recommendation. The User Agent Guidelines Working
Group expects to update it periodically with new techniques
and information about implementations that satisfy the guidelines.

This is a W3C Working Draft for review by W3C Members and other
interested parties. It is a draft document and may be updated,
replaced or obsoleted by other documents at any time. It is
inappropriate to use W3C Working Drafts as reference material or to
cite them as other than "work in progress". This is work in
progress and does not imply endorsement by, or the consensus of,
either W3C or participants in the WAI User Agent (UA)
Working Group.

The implementation examples indicate that a checkpoint has already
been fully or practically implemented by some type of user agent. Each
checkpoint links to information about existing and proposed
techniques for satisfying the checkpoint in
Techniques for User Agent Accessibility Guidelines 1.0 [UAAG10-TECHS].

Note. Where "no information is available", it may
be that there are not implementations today, that the Working Group is
not aware of any, or that the authors have not yet added the
information to this document.

Most users will be able to verify that most checkpoints have been
satisfied. Those checkpoints that may be difficult to verify
without vendor documentation or support are noted.

Detailed knowledge of the user agent functionality and the
operating system APIs and resources used to implement a feature is
typically needed to test these checkpoints. People other than
developers may be able to verify conformance through interaction with
native features of the user interface and compatibility testing with
assistive technology. But in these cases the person may not have
knowledge of all the functionalities of the user agent or be able to
test with all assistive technologies. In the case of assistive
technologies it may not be clear if the detected problems reside in
the user agent using appropriate interfaces to export information or
the assistive technology not taking advantage of information that the
user agent is making available.

This checkpoint must be satisfied by user agents,
otherwise one or more groups of users with disabilities will
find it impossible to access the Web. Satisfying
this checkpoint is a basic requirement for enabling
some people to access the Web.

This checkpoint should be satisfied by user
agents, otherwise one or more groups of users
with disabilities
will find it difficult
to access the Web. Satisfying this checkpoint
will remove significant barriers to Web access for some
people.

This checkpoint may be satisfied by user agents
to make it easier for one or more groups of users
with disabilities to
access information. Satisfying this checkpoint will improve
access to the Web for some people.

1.1 Ensure that every functionality available through the user interface is also available through every input device API supported by the user agent. Excluded from this requirement are functionalities that are part of the input device API itself (e.g., text input for the keyboard API, pointer motion for the pointer API, etc.) [Priority 1]
(Checkpoint 1.1)

Note. The device-independence
required by this checkpoint applies to functionalities
described by the other checkpoints in this document
(e.g., installation, documentation,
user agent user interface
configuration, etc.).
This checkpoint does not require user agents to use
all operating system input device APIs, only to make
the software accessible through those they do use.

May require developer documentation

Microsoft Internet Explorer 5.0 for MS-Windows provides extensive keyboard
and mouse support but does not provide device-independent
access to all functionalities.

Operasoft Opera 3.60 for MS-Windows provides extensive keyboard and mouse
support but does not provide device-independent
access to all functionalities.

Do not bypass
the standard output APIs when rendering information
(e.g., for reasons of speed, efficiency, etc.).
For example, do not bypass standard APIs
to manipulate the memory associated
with rendered content, since
assistive technologies
monitor rendering through the APIs.

1.3 Ensure that the user can interact with all active elements in a device-independent manner. [Priority 1]
(Checkpoint 1.3)

For example, users who are blind or have physical
disabilities must be able to
activate text links, the links
in a client-side image map, and form controls
without a pointing device.
Note. This checkpoint is an important special case of
checkpoint 1.1.

May require developer documentation

Microsoft Internet Explorer 5.0 for MS-Windows: links and form controls

Netscape Navigator 4.x for MS-Windows: links and form controls

Operasoft Opera 3.6 for MS-Windows: links and form controls

No known native support for device independent access to elements that can
respond to scripting events.

1.5 Ensure every non-text message (e.g., prompt, alert, etc.) available through the user interface also has a text equivalent in the user interface. [Priority 1]
(Checkpoint 1.5)

Note.
For example, if the user interface provides
access to a functionality through a graphical
button, ensure that a text equivalent for
that button provides access to the same functionality
from the user interface. If a sound is used to
notify the user of an event, announce the event
in text on the status bar as well. Refer also to checkpoint 5.7.

2.2 For presentations that require user input within a specified time interval, allow the user to configure the time interval (e.g., to extend it or to cause the user agent to pause the presentation automatically and await user input before proceeding). [Priority 1]
(Checkpoint 2.2)

Real Player 7 (Version 6.0.7.362)
Users can pause and resume (or restart) presentations as needed. No control
over configuring pauses or slowing down presentation speed, however.

2.3 When the author has not supplied a text equivalent for content as required by the markup language, make available other author-supplied information about the content (e.g., object type, file name, etc.). [Priority 2]
(Checkpoint 2.3)

Lynx renders the text "IMAGE" when no text equivalent
is available for an HTML IMG element.

Opera 3.60 for MS-Windows renders the text "IMAGE" when no
text equivalent is available for an IMG element.

2.5 If more than one equivalent alternative is available for content, allow the user to choose from among the alternatives. This includes the choice of viewing no alternatives. [Priority 1]
(Checkpoint 2.5)

Real Player G2 and Real Player 7 (Version 6.0.7.362)
allow users to select captions based on natural language.

For example, if a multimedia presentation has several
captions
(or subtitles) available, allow the user to choose from among them.
Captions might differ in level of detail, address
different reading levels, differ in natural language, etc.

2.6 Allow the user to specify that text transcripts, collated text transcripts, captions, and auditory descriptions be rendered at the same time as the associated auditory and visual tracks. Respect author-supplied synchronization cues during rendering. [Priority 1]
(Checkpoint 2.6)

3.7 Allow the user to turn on and off support for scripts and applets. [Priority 1]
(Checkpoint 3.7)

Note. This is particularly important
for scripts that cause the screen to flicker, since
people with photosensitive epilepsy can have seizures triggered by
flickering or flashing, particularly
in the 4 to 59 flashes per second (Hertz) range.

Netscape Navigator 4.x for MS-Windows

Operasoft Opera 3.60 for MS-Windows

NN 4.61 for Linux: Yes, through the user
interface (Preferences/Advanced).

Note. These modules are defined in
DOM Level 2 [DOM2], chapters 1 and 2. Please refer to
that specification for information about which versions
of HTML and XML are supported and for the definition
of a "read-only DOM. For content other than
HTML and XML, refer to checkpoint 5.3. This checkpoint
is an important special case of checkpoint 2.1.

May require developer documentation

Microsoft Internet Explorer 5.0 for MS-Windows provides access to the DOM
through a COM interface. We have not verified whether
the implementation conforms to the DOM specification.

5.2 If the user can modify HTML and XML content through the user interface, provide the same functionality programmatically by conforming to the W3C Document Object Model (DOM) Level 2 Core and HTML modules and exporting the interfaces they define. [Priority 1]
(Checkpoint 5.2)

For example, if the user interface allows users to
complete HTML forms, this must also be possible
through the DOM APIs.
Note. These modules are defined in
DOM Level 2 [DOM2], chapters 1 and 2.
Please refer to DOM
Level 2 [DOM2] for information about which versions
of HTML and XML are supported. For content other than
HTML and XML, refer to checkpoint 5.3. This checkpoint
is an important special case of checkpoint 2.1.

May require developer documentation

Microsoft Internet Explorer 5.0 for MS-Windows provides access to the DOM
through a COM interface. We have not verified whether
the implementation conforms to the DOM specification.

Note. This module is defined in
DOM Level 2 [DOM2], chapter 5. Please refer to
that specification for information about which versions
of CSS are supported. This checkpoint
is an important special case of checkpoint 2.1.

For example, ensure that assistive technologies have access to information about the
user agent's current
input configuration so that
they can trigger functionalities through keyboard events, mouse
events, etc.

For example, the programmatic exchange of information required by
other checkpoints in this document must be efficient enough to
prevent information loss, a risk when changes to content or user
interface occur more quickly than
the communication of those changes. The techniques for this checkpoint
explain how developers can reduce communication delays, e.g.,
to ensure that assistive technologies have timely access to
the document object model
and other information needed for
accessibility.

Note. For reasons
of backward compatibility, user agents should continue to support
deprecated features of specifications. The current guidelines
refer to some deprecated language features that do not necessarily
promote accessibility but are widely deployed. Information about
deprecated language features is generally part of
the language's specification.

Note.
For example, when all frames of a frameset are displayed
side-by-side, allow the user to navigate among them
with the keyboard. Or, when frames are accessed or viewed one at a time
(e.g., by a text browser or speech synthesizer), provide
a list of links to other frames.
Navigating into a viewport makes it the
current viewport.

NN 4.61 for Linux:
Yes: View/Page Source for frames in a single window. Navigation
possible with the mouse. Navigation of history possible with a history
window, a pulldown menu, and arrow icons (also possible with
keyboard). Navigation of windows is done through the window manager
(Alt-Tab in my configuration). It is not possible to navigate
links sequentially in NN on Linux.

8.1 Make available to the user the author-specified purpose of each table and the relationships among the table cells and headers. [Priority 1]
(Checkpoint 8.1)

For example, provide information about table headers,
how headers relate to cells, table summary
information, cell position information, table dimensions, etc.
Refer also to checkpoint 5.3.
Note. This checkpoint is an important special case of
checkpoint 2.1.

NN 4.61 for Linux: Yes, colors controllable through
style sheets, *vlinkForeground in the defaults file, and
through the UI under Preferences/Appearance/Colors.
From there you can also enable/disable underlining.

8.3 Indicate to the user whether a link has been marked up to indicate that following it will involve a fee. [Priority 2]
(Checkpoint 8.3)

Note. This checkpoint is an important special
case of checkpoint 8.4.
The W3C specification "Common Markup for micropayment per-fee-links"
[MICROPAYMENT] describes how authors may mark up
micropayment information in an interoperable manner.

8.4 To help the user decide whether to follow a link, make available link information supplied by the author and computed by the user agent. [Priority 3]
(Checkpoint 8.4)

Information supplied by the author includes link
content, link title, whether the link is internal,
whether it involves a fee, and hints on the content type, size, or
natural language of the linked resource. Information
computed by the user agent includes whether the user has
already visited the link. Note. User agents
are not required to retrieve the resource designated
by a link as part of computing information about the link.

8.6 Make available to the user an "outline" view of content, built from structural elements (e.g., frames, headers, lists, forms, tables, etc.). [Priority 2]
(Checkpoint 8.6)

For example, for each frame in a frameset, provide a table
of contents composed of headers where each entry in the
table of contents links to the header in the document.
Note. The outline view does not have
to be navigable, but if it is, it may satisfy checkpoint 7.6.

9.3 Allow the user to configure notification preferences for common types of content and viewport changes. [Priority 3]
(Checkpoint 9.3)

For example, allow the user to choose to be notified (or not) that a
script has been executed, that a new
viewport has been opened,
that a pulldown menu has been opened, that a new frame
has received focus, etc.

NN 4.61 for Linux:
Yes. Indicates visually in status bar at bottom of browser the
percentage of a page loaded, the amount loaded, and whether loading
has stalled or terminated. I do not know whether this information is
made available through an interface.

The Real Player 7 (Version 6.0.7.362) status bar
includes loading information, elapsed and total
time, and whether clip is a live broadcast.

9.5 Indicate the relative position of the viewport in rendered content (e.g., the percentage of an audio or video clip that has been played, the percentage of a Web page that has been viewed, etc.). [Priority 3]
(Checkpoint 9.5)

Note. The user agent may
calculate the percentage
according to content focus position,
selection position, or viewport position,
depending on how the user has been browsing.

Microsoft Internet Explorer 5.0 for MS-Windows

Netscape Navigator 4.x for MS-Windows

Operasoft Opera 3.60 for MS-Windows

RealPlayer G2

The Real Player 7 (Version 6.0.7.362) status bar
shows elapsed time and total clip time.

For voice-activated browsers, allow the
user to modify which voice commands activate functionalities.
Similarly, allow the user to modify the graphical
user agent user interface for quick
access to commonly used functionalities (e.g., through buttons).
Refer also to checkpoint 10.5 and checkpoint 10.9.

10.5 Allow the user to configure the user agent so that the user's preferred one-step operations may be activated with a single input command (keystroke, voice command, etc.). [Priority 2]
(Checkpoint 10.5)

Note. User agents are not required
to provide single command activation of all user agent functionalities
at once, only some of them. This checkpoint is an important special case of
checkpoint 10.4.

For example, on some operating systems,
if a functionality is available from a menu, the
letter of the key that will activate that functionality is
underlined. Note. This checkpoint is an
important special case of checkpoint 5.9.

10.7 For the configuration requirements of this document, allow the user to save user preferences a profile. [Priority 2]
(Checkpoint 10.7)

Note. This includes user
preferences for styles, presentation rates,
input configurations,
navigation, views, and notification.
Users must be able to select from among available
profiles or no profile (i.e., the user agent default settings).

Microsoft Internet Explorer 5.0 for MS-Windows does, for information
that can be contained in user style sheets.

Operasoft Opera 3.60 for MS-Windows does, for information that can be
contained in user style sheets.

NN 4.61 for Linux: Yes, since configuration is
done through XResources, users can specify their own resources.